Elkem has developed a new product to improve the cast properties of both grey and ductile cast irons. This has been named Preseed™ preconditioner. This novel product may be added to the melting (induction melting) furnace or during metal transfer (cupola) resulting in increases to the nucleation levels.
By creating and stabilising long lasting particles which may then form the basis of nucleation, Preseed™ preconditioner has been seen to give marked increases in the mechanical properties of castings as well as improvements to the graphite morphology / matrix.
With careful use of Preseed™, foundries have been able to reduce expensive pig iron additions, create more stable and consistent castings and reduce overall costs.
There are very few dedicated preconditioners for cast irons available on the market. The need for more consistent base iron is increasing as the casting quality demands become more stringent. Based on fundamental research, Elkem has developed the preconditioner Preseed. This has been demonstrated to improve the final casting properties of the iron and have a longevity far superior to other so-called preconditioning agents, such as silicon carbide or high barium containing ferrosilicons.
As steel scrap quality deteriorates, foundries have to dilute the concentrations of such elements as manganese with increasing amounts of pig iron in order to produce, for example, highly ferritic irons. An alternative solution is to increase the base iron nucleation state so that more nodules are generated during solidification and hence reduce the pearlite percentage in the iron.
Preseed has been shown to achieve a long lasting increase in the nucleation levels, raising the low eutectic temperature, reducing the degree of recalescence and increasing the graphite precipitation phase of the freezing cycle. The result in ductile irons is an increase in the nodule count and improvements in the resulting mechanical properties and shrinkage tendency.
In grey irons, Preseed has been shown to improve graphite morphologies, reduce shrinkage and chilling tendencies, and improve mechanical properties. Elimination of undesirable graphite forms, such as type D and E graphites have been achieved.Preseed is a cost effective treatment which demonstrably reduces down-stream processing and costs.
Preseed may be used effectively in both grey and ductile cast irons where there is a need to improve consistency, reduce pig iron or other alloy additions and to improve casting properties.
Preseed™ is a trademark of Elkem AS.